Scientific Method —

Does high-fructose corn syrup make you fatter?

A new study suggests that there's a clear link between high-fructose corn …

The use of high-fructose corn syrup (HFCS) has boomed in recent years, driven primarily by its low cost and ease of use in beverages. The increased levels in the US diet have roughly corresponded to the timing of the obesity epidemic, which has led many to suspect there's a causal relationship. But definitive evidence that the body responds to HFCS in a manner that's distinct from any other caloric intake has been difficult to come by. A group of researchers from Princeton now claim to have provided a conclusive demonstration that HFCS triggers obesity in rats, but there are enough oddities in the data that it would be wise to reserve judgement until the work is replicated.

Chemically, HFCS is a mix of fructose and glucose, the two components of table sugar. Unlike in table sugar (sucrose), however, the two are not chemically linked, and there's a slight excess of fructose instead of the 50:50 mix present in sucrose. These differences are relatively minor in the grand scheme of things, but there has been a consistent flow of studies that suggest the body responds quite differently to sucrose and HFCS, including indications of different fat metabolism and insulin responses. One idea that that's been proposed is that fructose doesn't induce the same sense of satiation that glucose does, meaning that we're less likely to stop eating after we've ingested sufficient calories.

In the absence of a coherent picture on the biochemistry, the new study attempts to look at the longer term impact of access to HFCS. The Princeton study set up groups of age-, weight-, and sex-matched rats, and gave them access to all the chow they could eat. In addition, different groups of rats were given access to an HFCS solution for either 12 or 24 hours; another group were given a similar sucrose solution, and a control group was simply given water. The amount of calories consumed, both from rat chow and sugar solutions, was monitored daily, and the rats were weighed every week. Two experiments were run, one for two months, the second for six.

At the end of the shorter trial, the male rats with 12-hour access to HFCS had gained significantly more weight than the group given access to sucrose—even though they actually consumed fewer calories in liquid form (the sucrose group ate enough chow to make up for the difference). That seems pretty important until you look at some of the details: the 24-hour HFCS group consumed roughly the same number of calories, on average, as their 12-hour peers, but didn't put on the same amount of weight. In fact, the 24-hour group wasn't significantly different (in the statistical sense) than either the sucrose or chow-only controls.

The longer-term study could have clarified exactly what was going on here, but the authors eliminated the sucrose group, "Since we did not see effects of sucrose on body weight in Experiment 1." In this experiment, the 24-hour group actually gained more weight than the control population as early as three weeks into the experiment. In fact, they gained more weight than the 12-hour group, although this difference isn't statistically significant. It doesn't appear that the authors attempted to explain why the two experiments seem to have produced different results.

At the end of this study, the fat pads were dissected out and weighed, and the abdominal fat pads of the 12-hour group were significantly different from those of the chow-only control. However, the abdominal fat of the 24-hour group (which, remember, gained more weight) wasn't significantly heavier than the control group.

To confuse matters further, the authors also ran a group of females through the long-term study protocol, and this time included a group with access to a sucrose solution. Females gained less weight in general than males, and those with 12-hour access to either HFCS or sucrose solutions finished the experiment in a statistical dead heat. Only the 24-hour HFCS group showed a significant increase in weight gain (and had a corresponding increase in fat deposition).

(One other thing that seems worth noting is that the procedures took place during a time when the rats normally gain weight. For example, the chow-only control group doubled in weight during the long-term experiment, while the HFCS group bulked up by roughly 260 percent.)

Although some of the results are suggestive, given the somewhat confusing and, in some cases, contradictory nature of the result, it would seem to be appropriate to interpret them with caution, and go back and start a larger population of rats on a study with a more consistent design. The authors haven't gone that route, as their conclusion (in its entirety) reads, "In summary, rats maintained on a diet rich in HFCS for 6 or 7 months show abnormal weight gain, increased circulating TG and augmented fat deposition. All of these factors indicate obesity. Thus, over-consumption of HFCS could very well be a major factor in the 'obesity epidemic,' which correlates with the upsurge in the use of HFCS."

Their host institution, Princeton, has also put out a press release that also glosses over the uncertainties. (It also has a hilarious picture of the research group attempting to look like they're doing science.) Wikipedia's HFCS entry has already been updated, and links to the corn industry's response. Fortunately, though, the mainstream media has largely given this paper a pass, which may cut down on the confusion as we wait for a larger, more definitive study.

Does anyone seriously consider this issue still open to debate? I did an unpublished literature review of this topic a few years back and the evidence and biochemistry mechanisms seemed to be pretty well understood. Specifically fructose requires GLUT5 transporter which is predominantly located in the liver. So fructose is mainly a "liver" food where as sucrose is an "all over food" seeing as how just about every cell has the GLUT1 and GLUT4 transporters. You couple that with the fact that fructose gets to skip the first few enzymes in the sucrose metabolic pathway which can alter the balance of the randle cycle.

So this basically leads to high calories sensing in the liver which communicates to the brain this state via afferent projections of potassium inwardly rectifying neurons. When I did my research these neurons had been viral traced and showed that sniping them resulted in greater than 50% reduction in glucose disposal to oral glucose challenge. Couple this with the effects that increased nutrient sensing in the liver has on cotrisol metabolism (directly related to the increased abdominal fat pat weight via 11-beta-HSD disruption).

Anyway the evidence seemed pretty clear cut to me. The lesson for humans seemed to be that fructose should generally be avoided unless one regularly exercises with sufficient length and intensity required to somewhat deplete liver glycogen content. Its a great sugar for repleting depleted liver glycogen stores though.

Also worth noting that rats have more trouble with excess caloric load on the liver than humans due to the peroxisome proliferation that happens in rats but not humans.

From: http://www.corn.org/princeton-hfcs-study-errors.htmlTranslating the study’s reported rat intakes to human proportions, the calories gained from high fructose corn syrup would be equivalent to about 3000 kcal/day all from that single source. In comparison, adult humans consume about 2,000 calories per day from all dietary sources. Such intake levels for the study animals would be the equivalent of humans drinking a total of 20 cans of 12 ounce sodas per day - a highly unrealistic amount.

I always wondered if Big Food will one day end up in Big Smoking's shoes in front of congress on HFCS. "How long did big food know HFCS was bad for people, and why didn't they speak up as America got fatter and fatter?"

From: http://www.corn.org/princeton-hfcs-study-errors.htmlTranslating the study’s reported rat intakes to human proportions, the calories gained from high fructose corn syrup would be equivalent to about 3000 kcal/day all from that single source. In comparison, adult humans consume about 2,000 calories per day from all dietary sources. Such intake levels for the study animals would be the equivalent of humans drinking a total of 20 cans of 12 ounce sodas per day - a highly unrealistic amount.

Whoever wrote that has apparently never been to America.

Most people I know still think the Nutrition Facts label is for the entire product, rather than a single serving, so I'll hear them occasionally say "this soda only has 100 calories!"...yeah, for one serving. There's 2.5 servings in that bottle.

Education has to play a big part in the epidemic. I'd like to see a study that tackles the causal relationship between education and obesity.

I thought drug companies used to feed genetically bred rats predisposed to diabetes high-fructose diets in order to get them into diabetic states to test diabetes drugs. Maybe I just heard that as hear-say, but I've always known from a personal level that fructose causes hunger-surges in me. Diets that prescribe eating fruit in the morning, that's like setting me up for a binge-eating session at night, since the insulin has been jacked up at the start of the day. I think the liver is only capable of processing up to 2 pieces of fruit worth of fructose per day as a glycogenic process, and the rest gets converted to triglycerides for fat storage. The problem arises when things like sucrose get broken down into glucose + fructose, and all that extra fructose starts screwing with your metabolism. Fructose is treated a little differently than other sugars, so it was prescribed to diabetics long ago since it supposedly didn't impact their blood sugar. But it does impact insulin levels.

We also have to consider that fruit is a "seasonal sugar" that folks evolving in some climates don't have access to at all or year-round. EG: Eskimo's. Their metabolism got shot to hell once sugar and fruit made its way up there. Meanwhile, more equatorial metabolisms got shot to hell when high-fat made its way back down (Aztecan and Mayan off-shoots do well on high-grain diets, but pork up readily once you start frying everything ... Eskimos do well on high-fat diets, but pork up readily once you add sugar.) Note that all "junk foods" are always some combination of fat+carb/sugar, which is very hard to find together in nature. EG: you don't see "pizza plants" in nature, and animals hunted for food don't have some large carbohydrate reservoir in them that you can eat.

Trans fats, corn syrup, fluoridated water (tin-foil hat me all you want...it was used to treat hyperthyroidism then stopped, but now we toss it in our drinking water). Welcome to the United States of McDonalds.

One big concern is not so much that HFCS is used, but that it's used so universally. It's not just in soda. It's adding sugars to a lot of processed foods and to a lot of diets.

I wouldn't say it's responsible for the obesity epidemic, but it certainly contributes to it. The obesity epidemic is more complicated than just one thing.

There's availability of food, the quality of the food, how much of it's pre-processed (and, therefore, likely to include HFCS), individual activity, etc.

It will take several more independent (and less borked) studies before I begin to reconsider HFCS as something that's not a health issue.

It's used to mask the fact that a lot of stuff tastes like *ss. It tastes like *ss because of the use of crap components and cost cutting. It's added to industrialized psuedo-food to make it taste better generally and make up for general crappiness.

Take everything you eat, add some extra sugar to it and you will probably get fatter.

Imagine that...

Then there's basic over eating, escalating portion sizes and treating stuff like frosting as food group.

The reason why weight can increase but fat stays the same is because sugar takes water to digest. What was measured was water weight gain, and is the first 10-15lbs of weight lost while on the Atkins diet. There is no reason why in two weeks, an adult can lose 10 lbs (35000 calories) in 14 days while eating meat and veggies. It would require an intake of only 1000 cal/day, which isn't what people do on Atkins.

In comparison, adult humans consume about 2,000 calories per day from all dietary sources.

That is funny. It would be more accurate to say that the USDA recommends a 2,000 calories per day diet, which has nothing to do with what people actually do.

Quote:

Most people I know still think the Nutrition Facts label is for the entire product, rather than a single serving, so I'll hear them occasionally say "this soda only has 100 calories!"...yeah, for one serving. There's 2.5 servings in that bottle.

I do not see that very much, but math is hard. I like Europe's idea of also listing the total calories in the package as a separate number. Probably not very useful for a jar of pickles, but great for a soda or a bag of chips.

Amusing anecdote: according to Dill, one serving of pickles is 2/3rds of a pickle. What the ?

I'm not personally 100% against corn syrup, but it's in far too many products that don't generally require sweetening. Pasta sauce, baby formula, hell even vanilla extract (seriously.). I would be critical of sugar under similar circumstances (and I was, until it was replaced.)

Sodas have also been ruined by HFCS. Taste one with and one with sugar, and tell me the latter isn't superior.

Take everything you eat, add some extra sugar to it and you will probably get fatter.

This is it, IMO. I don't think it's that the biochemistry of HFCS is so much different from sugar, it's that we've decided to buy sweeter and sweeter products over time, and we're using the corn syrup to do it. We have an embarrassment of caloric riches in this country. Only in the U.S. have I seen obese homeless people.

Both the Ars article and @spookware mix up glucose and sucrose. The fructose to glucose ratio in sucrose is 50:50 and in HFCS its 55:45. That's 5%. Entirely different than a diet of pure fructose or pure glucose.

Its not the HFCS. Physically its the total calories and the body's response to sweeteners in general leading to behavioral changes and insulin resistance. Psychologically, eating too many sweet things makes you want to eat too many sweet things.

Robert H. Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology, explores the damage caused by sugary foods. He argues that fructose (too much) and fiber (not enough) appear to be cornerstones of the obesity epidemic through their effects on insulin.

Yes, Lustig's video is very good. I had intended to post it myself, but you beat me to it.

Never mind the rats the Ars writer mentions, how about all the children who've been through Lustig's paediatric clinic?

Rather surprising to find that fructose (whether from sucrose or not) is metabolized by the liver in much the same way as alcohol. You've heard of the "beer belly" now meet the "coke belly" -- only this one is on little kids. They deserve better.

It's been a suspicion for a while. I hope we see some kind of action. It's not very likely with what a towering industry corn is for North America.

Here is the true answer, produced by my high levels of scientific knowledge and extensive study. Complex concepts such as these are often best described in psuedo-code:

if calories in > calories out:then you_get_fatter()endif

Sure then corn syrup can make you fatter. So can broccolli if you eat enough of it. Especially if you fry it.

Calories being a measurement of energy. You eat more energy then you output then you get fat. How your body reacts to certain types of sugars or if you have some sort of glandular disorder is actually almost irrelevent. Those things can certainly affect your behavior, but fundamentally it's your behavior that makes you fat.

Do you think that anything else going on in society from 1950's to the 1980's could of possibly contributed to the rise in fat asses?

I'll give you a few hints:* Air conditioning* Television* Automobiles* Fast food* How above things ranked in terms of quality and affordability.

From: http://www.corn.org/princeton-hfcs-study-errors.htmlTranslating the study’s reported rat intakes to human proportions, the calories gained from high fructose corn syrup would be equivalent to about 3000 kcal/day all from that single source. In comparison, adult humans consume about 2,000 calories per day from all dietary sources. Such intake levels for the study animals would be the equivalent of humans drinking a total of 20 cans of 12 ounce sodas per day - a highly unrealistic amount.

Whoever wrote that has apparently never been to America.

Whoever wrote that is lying through their fucking teeth too. We produce over 4500 calories of food per day per person in Amurka. Of course, that doesn't mean we eat 4500 calories per day. Most estimates I see say we actually eat upwards of 3700 calories per day.

If you want to see something truly consciousness raising about HFCS and food in Amurka, watch this video. It's a lecture given by Robert Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology on the subject of HFCS and sugar in the American diet. It covers the entire rise of HFCS and the corn lobby in Amurka and continues to discuss the biochemistry involved in metabolizing HFCS/fructose and why it's so bad for us.

When you're finished with that, go buy Michael Pollan's The Omnivore's Dilemma and In Defense of Food and read them.

Edit: And shit, I wasn't even the first person to post that lecture. Well, at least now you know two other people here can vouch for the content of the video. Go watch it. Now.

I guarantee you that a large intake of non-HFCS sodas will also make you obese.

I'd beg to differ. Just because you consume it doesn't mean you WILL become obese.If you lead an active lifestyle and are not sedimentary you should be able to EASILY burn off the excess calories. Or if you have a naturally high metabolism you could also be able to handle the high caloric intake (that's why I stayed the same weight throughout college even though I loved soda and was glued to the computer labs).

The reason why weight can increase but fat stays the same is because sugar takes water to digest. What was measured was water weight gain, and is the first 10-15lbs of weight lost while on the Atkins diet. There is no reason why in two weeks, an adult can lose 10 lbs (35000 calories) in 14 days while eating meat and veggies. It would require an intake of only 1000 cal/day, which isn't what people do on Atkins.

Its water weight...

Interesting, that corresponds with my own experiences. I know I eat a lot of sugar because I'm lazy and don't bring a lunch to work, thus I have a soda while eating out.I have to drink 2-3Litters of water day to feel like I'm hydrated. Yes, I'm overweight and always figured there was a link between the two.

It's been a suspicion for a while. I hope we see some kind of action. It's not very likely with what a towering industry corn is for North America.

Here is the true answer, produced by my high levels of scientific knowledge and extensive study. Complex concepts such as these are often best described in psuedo-code:

if calories in > calories out:then you_get_fatter()endif

Sure then corn syrup can make you fatter. So can broccolli if you eat enough of it. Especially if you fry it.

Calories being a measurement of energy. You eat more energy then you output then you get fat. How your body reacts to certain types of sugars or if you have some sort of glandular disorder is actually almost irrelevent. Those things can certainly affect your behavior, but fundamentally it's your behavior that makes you fat.

Do you think that anything else going on in society from 1950's to the 1980's could of possibly contributed to the rise in fat asses?

I'll give you a few hints:* Air conditioning* Television* Automobiles* Fast food* How above things ranked in terms of quality and affordability.

Do yourself a favor and watch the YouTube video linked above.

Lustig makes a very convincing case (including laying out the metabolic pathways involved) that eating, say, 1 kcal of sucrose is not equivalent to eating 1 kcal of fructose. A calorie of one is NOT equal to a calorie of the other. As Spookware (and Lustig too) points out above, fructose can only be metabolized in the liver, and the liver metabolizes it into lipids. In short, even if you're eating a 2 kcal diet, if your diet is composed of fructose, you're going to be fatter than someone else eating a 2 kcal diet of sucrose (or other calorie sources). Oh, also, from the way you immediately jumped to the personal responsibility mantra, I'm going to assume you're an Ayn Rand fan or other libertarian/conservative fanatic. Am I right?

I can buy different metabolic pathways causing very different bodily reactions to fructose vs glucose, but it's going to take more than a youtube video to convince me that that's the root cause of rampant obesity. I'm much more inclined to believe it's excess sugar generally.

Even though it's mentioned in the article and comments several times, some commenters seem unaware that HFCS is *not* pure fructose. Truthiness seems held in high regard around the HFCS issue in general, so I look forward to a more complete study. In the meantime, I'm going to keep trying to eat things I cook myself as often as I can.

Over the course of my life, I've become sensitive to fructose in foods thanks to complications with my immune system - and now have to avoid things like apples, onions, corn etc. which are high in fructose and very prevalent in food production (apple-derived products especially).

I'm probably on the side of underweight for my height, but thankfully here in Australia much of our sugar is derived from cane - which doesn't affect me in the same way corn-based sugars do.

HFCS and the high volume of it seems quite dangerous - not just for obesity, but for things like developing intolerances to fructose in general due to too-high levels of intake.

Anyway the evidence seemed pretty clear cut to me. The lesson for humans seemed to be that fructose should generally be avoided unless one regularly exercises with sufficient length and intensity required to somewhat deplete liver glycogen content. Its a great sugar for repleting depleted liver glycogen stores though.

Strabo wrote:

Lustig makes a very convincing case (including laying out the metabolic pathways involved) that eating, say, 1 kcal of sucrose is not equivalent to eating 1 kcal of fructose. A calorie of one is NOT equal to a calorie of the other. As Spookware (and Lustig too) points out above, fructose can only be metabolized in the liver, and the liver metabolizes it into lipids. In short, even if you're eating a 2 kcal diet, if your diet is composed of fructose, you're going to be fatter than someone else eating a 2 kcal diet of sucrose (or other calorie sources).

Ok... But HFCS and normal sugar only differ by a few percentage points in the amount of fructose. So shouldn't we avoid normal sugar as much as HFCS?

In then end we can theorize about this all we want, we really need a conclusive solid study testing a complete system (ie. an animal) to figure this out. I try to avoid HFCS as well but its not some crazy hate/fear of it, its just that most products that have it as an ingredient are garbage.

Ok... But HFCS and normal sugar only differ by a few percentage points in the amount of fructose. So shouldn't we avoid normal sugar as much as HFCS?

In then end we can theorize about this all we want, we really need a conclusive solid study testing a complete system (ie. an animal) to figure this out. I try to avoid HFCS, as well but its not some crazy hate/fear of it, its just that most products that have it as an ingredient are garbage.

QFT.

I wish we used sugar in soda in the US. At least in "cola" variants. Even if its more expensive, the colas I've been able to get my hands on that have cane sugar in them are so tasty. Probably just as bad for me as HFCS soda, though.